The purpose of this study is to develop a design method of a flexible mechanical system using a hydrostatic skeleton driving mechanism. The system consists of two types of flexible bags in order to separate the roles into a structural part and an actuator part. One is a constant pressure bag as a structural part, and the other is a pressure tunable bag as an actuator part. There are remarkable advantages of using this system as listed below: i) Because of the flexibility, the system can be applied safely to various kinds of workspaces where living beings and mechanical systems work together. ii) Because of using two types of bags, driving efficiency of the system is higher than that of other flexible systems using only one type of bag. The theoretical design method of the system is required to realize these advantages. In order to realize the design method, it is important to calculate the structural strength of the structural part and driving force generated by the actuator part. In this paper, strength evaluation of the structural part is performed by nonlinear FEA. From the comparison between the analytical result and measurement results, deflection of the structural part is obtained. On the other hand, the driving force that is generated by the actuator part is also analyzed. Based on the analytical results, an empirical equation about the driving force is induced. The validity of the empirical equation is confirmed by the comparison between measurement values and the values of the empirical equation. These results will contribute to an optimum design of the proposed flexible mechanical system.

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We have developed a coupled system simulator that can be used in a model-based development method to improve the effectiveness of an airscrew compressor. A feature of this simulator is that it consists of models of an electrical and a mechanical system, and it can be investigated by using coupled analysis. The mechanical model consists of a compressor and a power transfer mechanism. The compressor model is capable of calculation covering all operation speeds combining the load torque of regular operation from theoretical calculation of gas compression, and the load torque at the time of starting from the model created by the data obtained from the experiment. The electric model consists of a power supply, an inverter, and a brushless DC motor. Since the motor model can directly use the magnetic field analysis result, motor evaluations can be done quickly. We set out an outline of the modeling, provide a detailed model of the compressor, and explain the result of our calculation.

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We have developed a hydraulic McKibben artificial muscle, which is small-sized and lightweight compared to other conventional actuators. In this paper, we have applied this muscle to a power robot hand. The hand fingers consist of metal links and muscles, and the contraction of the muscles generates the bending motion of the fingers. This hand has large holding capacity and shape adaptability to grasp objects. The experiments show that the maximum holding force of the hand is 4000N, and it can hold three types of different shaped objects; cylindrical objects having a diameter of φ267mm and φ165mm and a squire pole that is 200mm on a side. The hand has the potential for being applied to rescue robots in disaster areas and forestry industry, for example.

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